An Insight of AZ91D/WS2 Surface Composite developed by FSP

Abstract

The present work surface modifications of AZ91D magnesium alloy using friction stir processing (FSP). The tungsten disulfide (WS2) reinforcement particles are used in friction stir processing of AZ91D magnesium alloy. FSP of the alloy created the coating by depositing the reinforcing particles into a surface groove. Coating properties determined by metallography, hardness, and pin-on-disc wear testing. The wear resistance of the friction stirs processed coating is due to grain boundary pinning and dispersion hardening induced by tungsten disulfide powder. The grains are more elongated in the stir zone processed FSP. The results revealed that, after FSP, the grains of the placed coating were importantly refined, and the coarse β-Mg17Al12 phase was damaged and dispersed into the ά-Mg matrix, primary to the microstructure modification. In the stir zone, the hardness of AZ91D base material is 76Hv enhanced to 96Hv due to tungsten di-sulfide material. The wear parameters of normal load 10N, 20N, and 30N sliding velocities of 1, 2, and 3 m/sec are performed. The surface composite coating with tungsten disulfide was found to possess better wear resistance than the base material. The investigation of wear track showed various worn surfaces through Scanning electron microscope (SEM) micrographs to understand the wear mechanism of delamination, abrasion, and melting formation.